A droplet of pure mercury has a density of 13.6 g/cm3. What is the density of a sample of pure mercury that is 10 times as large as the droplet?
The density will be the same. Since the two materials are identical, there will be an equal density in both drops.
In the first drop, lets say there is 1 cm3 of pure mercury, weighing 13.6 g. The density is 13.6g/1 cm3, or 13.6g/cm3.
In the second sample, 10 times larger, it is 10cm3 of pure mercury, but it also has 10 times larger mass, at 136g. This is 136g/10cm3, which simplifies to the same 13.6g/cm3.
Hope that helps!